Car coupler



Nov. 11, 1952 w. .1. METZGER 2,617,539

CAR COUPLER Filed April 15, 1949 2 SX-lEETS--SHEET 1 INVENTOR.

WlLUAM d. METZGER Fig.4 6%! AT TOR NE Y Nov. 11, 1952 w. .1. METZGER CAR COUPLER 2 SHEETS-SHEET 2 Filed April 15, 1949 :58 to H23 H55 INVENTOR. WILLIAM J. E ZGER MU ATTORNEY l atented Nov. 11, 1952 UNITED NT OFFICE CAR COUPLER Ohio Application April 15, 1949, Serial No. 87,601

2 Claims.

This invention relates to railway car couplers.

In knuckle type couplers such as the Association of American Railroads standard E coupler the knuckle is swung open b means of a horizontally positioned knuckle thrower which is mounted for rotation about a vertical axis and which has an arm that bears against a pad on the knuckle in response to actuation of the uncoupling mechanism. As the knuckle thrower is caused to rotate the force exerted by the end of the thrower arm against the knuckle pad pivots the knuckle about its pivot pin to open position.

Frequently there is difficulty in throwing open the knuckle of existing couplers. This is due at least in part to the nature of the engagement between the knuckle thrower arm and the knuckle pad as the knuckle is swung open during actuation of the uncoupling mechanism.

I have found that by forming the knuckle pad with an improved contour the resulting engagement between the knuckle thrower arm and the pad is such that the knuckle may be swung to open position by the application to the knuckle thrower of an appreciably lesser force than is necessary with existing couplers.

The various features and advantages of the invention will be apparent from the following description taken in conjunction with the drawings in which:

Fig. 1 is a horizontal sectional View of an -A. A. R. standard E coupler embodying the invention.

Fig. 2 is a partial sectional view taken along line 22 of Fig. 1.

Fig. 3 is an enlarged fragmentary plan view showing the coupler knuckle and the knuckle thrower of Fig. 1 in the same relative position they occupy in the coupler head. Also, for the purpose of illustration the knuckle thrower engaging pad and the knuckle thrower have been shown in their relative positions corresponding to closed, intermediate, and open positions of the knuckle. In addition to facilitate comparison the corresponding positions of the existing E coupler knuckle pad and the knuckle thrower have been shown in dot-dash.

Fig. 4 is an enlarged sectional view showing a,

modification of the knuckle thrower engaging pad applied to an E coupler knuckle, the knuckle thrower itself being shown in plan.

Referring to the drawings there is shown an A. A. R. (Association of American Railroads) standard E coupler embodying my invention. The coupler comprises a head 8 having a guard arm l and a knuckle l2 pivotally connected to the head by means of a vertical pivot pin 14.

The knuckle has a nose It disposed transversely inwardly of pin 14 as seen in Fig. 1. The knuckle also has a tail i8 which extends rearwardly of pin I 4 when the knuckle is in closed position. The underside of the tail is provided with a pad 29 having a vertical rearwardly extending surface 22 which is adapted to be engaged by the arm 24 of knuckle thrower 26. The contour of surface 22 will be defined in a succeeding part of this specification. The knuckle thrower is mounted for horizontal pivotal movement about a trunnion 23 which is received in an opening disposed rearwardly of pin M in the coupler head. Thrower 26 is positioned beneath tail #8 and is formed with another arm 30 on the side of trunnion 28 opposite from that of arm 24. Arm 30 is adapted to be engaged by lock member 32 when the latter is raised during actuation of the coupler uncoupling mechanism, the construction and operation of which is well known in the art. As the lock is raised out of its locking engagement with knuckle tail l8 its leg portion is moved rearwardly against thrower arm 30, causing the thrower to pivot, whereby arm 2:1 thereof through its engagement with surface 22 of pad 20 rotates the knuckle to open position.

In the present E coupler the knuckle pad 20 is provided with a flat contact surface 34 (shown in Fig. 3 in dot-dash) disposed substantially in alignment with the inner side 38 of knuckle thrower arm 24 when the knuckle is in closed position, the end of arm 24 being shown in engagement with surface 34. Surface 34 if extended toward the pivotal axis of the knuckle will pass outwardly of the axis as viewed in Fig. 3.

In Fig. 3 the knuckle I2 is shown in closed position with the knuckle thrower arm 24 in contact with surface 22 of pad 20. Dot-dash line 34 as aforementioned represents the contact surface of the pad as found in existing E couplers. Other relative positions of thrower arm 2 and surfaces 22 and 34 have been illustrated in this view and represent the relationship which exists for various pivoted positions of the knuckle.

With the knuckle in closed position as in Fig. 3 thrower arm 24 engages the rearward extremity of surface 22 at a, while for the same position of the knuckle the effective point of contact of arm 24 with the pad, when provided with existing surface 34, would be at a. As arm 24 is caused to rotate about its pivot 28 in a counterclockwise direction its point of contact with surface 22 moves progressively forward to point I) at which point the knuckle has pivoted about 5 degrees toward open position. For this position of the knuckle the arm 26 would contact surface 34 at b. Further rotation of the knuckle thrower moves the point of contact between arm 24 and surface 22 to point 0, while point represents the corresponding engagement of the arm with surface 34. The positions of arm 24 corresponding to points 0 and 0 represent the forwardmost positions attained by the arm with respect to surfaces 22 and 34 respectively. the thrower is pivoted the point of contact of arm 24 with surface 22 moves rearwardly until the point d is reached, at which position the knuckle is fully opened. Point d represents the corresponding point of contact between arm :23 and surface 34 for the fully opened knuckle. It will be noted in Fig. 3 that during the knuckle opening operation the surface '22 of pad passes from one side of line Y which joins the pivotal centers of the knuckle and the knuckle thrower to the other side of this line. Line Y is disposed about midway between the positions of surface 22 corresponding to closed and open positions of the knuckle. Thus the knuckle thrower arm 24 remains in contact with surface 22 throughout the knuckle opening operation.

A vertical reference plane X passing through the pivotal axis of the knuckle and tangent to the rearward extremity of surface 22 will be used in defining the contour of this surface. At approximately the point of tangency of plane X with surface 22, this surface diverges from the plane along a curve in a forward direction. Preferably surface 22 at its rearward extremity is tangent to rounded end surface 38. mately midway between the ends of surface 22 its contour changes to a reverse curve which is tangent to the aforementioned portion of the contour and which continues to diverge from plane X until it merges with the fillet portion All adjacent hub 42 of the knuckle. It will be observed that with respect to plane X surface 22 diverges therefrom and is positioned on the same side thereof as the knuckle nose It. In addition it will be noted that surface 22 also diverges from the Plane of inner surface of arm 24 of the thrower when the knuckle is in closed position and arm 25 is in contact with surface 22. On the other hand surface 34 on the pad of the existing knuckle diverges from plane X on the opposite side thereof from surface .22

Also it is to be observed that surface 22 is disposed on the same side of plane X as the longitudinal center line of the coupler, whereas surface 34 is disposed on the opposite side of plane X from the longitudinal center line.

A purpose in forming the contour of surface 22 as above described is to cause thrower arm 24 to engage this surface at a point farther from the pivotal axis of the knuckle than itdoes with existing surface 34. Thus the initial contact point a is appreciably rearward of point a. This therefore increases the moment arm of the point a with respect to the pivotal axis of the knuckle and decreases its moment arm with respect to the pivotal axis of the knuckle thrower, so that for any given rotative force applied to the thrower a greater force for turning the knuckle will be exerted by arm 25 against surface 22 than would be exerted against surface 3 3. While this gain in leverage is particularly desirable in starting rotation of the closed knuckle, a gain in leverage exists throughout the opening. of the knuckle, as may be seen by a comparison of the moment arms of contact points I c and .d with b, c and Thereafter as Approxid. In each of the positions of the knuckle corresponding to these points the moment arms with respect to the pivotal axes of the knuckle end thrower are such that a gain in leverage is provided. The result ofthe gain in leverage is that a lighter force may be applied by a workman to the handle of the conventional uncoupling rod to effect opening of the knuckle.

Another important purpose in devising surface 22 as above described is to reduce the amount of friction between thrower arm 24 and this surface during opening of the knuckle, particularly during the initial rotation thereof. This is effected by the downhill relationship which exists between thrower arm 24 along surface 22 as compared with the movement of arm 24 along sur- .face 34. In other words during opening of the knuckle the thrower arm 24 in effect ascends a surface which slopes a lesser amount when moving along surface 22 than when moving along surface 34. This is apparent in Fig. 3 wherein in closed position of the knuckle the curved surface 22 diverges from the contact surface of arm 24 a greater amount than the flat surface .34. The relative downhill action thus obtained with the surface 22 serves to decrease the force needed to be applied to the thrower to open the knuckle.

Actual tests on full sized couplers having knuckles provided "with thrower engaging surfaces 22 and 3 3 have been made to determine the force required to be applied to the conventional uncoupling rod handle 'to open the knuckles. These tests show an average reduction of about 20 per cent in the force applied to the uncoupling rod handle to open the knuckle when the latter is provided with knuckle thrower contact surface 22 than when the knuckle has the existing surface 34. Also, this advantage is obtained with an increase in the rotation .of the uncoupling rod handle of only 2 degrees over the rotation necessary with present surface 34 in order to throw the knuckle completely open.

A modification of my invention is illustrated in Fig. 4 wherein the pad 29 of knuckle I2 is formed with a flat knuckle thrower engaging surface 44. This surface is disposed so as to diverge from reference plane X, which passes through the pivotal axis of the knuckle and is tangent to the rearward extremity of the surface, in the same manher as surface 22 of the preceding embodiment. The gain in leverage is similar to the gain provided by surface 22. However, a slightly greater leverage is obtained with surface 44 at thestart of opening of the knuckle. This is effected through reduction of the radius of the curved portion 46 which joins surface 44 with end surface l8, thereby causing the point of contact ve between arm 25 and surface 44 to occur at a greater distance from the pivotal axis of the knuckle and at a shorter distance from the Pivotal axis of the knuckle thrower. In addition the relative downhill action between thrower arm 22 and surface 64 is subtsantially the same as is obtained with surface :22.

It will be appreciated that in order to obtain greater leverage against the knuckle with the thrower arm to facilitate opening of the. knuckle, it was not possible merely to extend knuckle pad 20 rearwardly in the existing coupler. Any such rearward extension is prohibited y the clearances which must be maintained to permit the knuckle to swing without interference to open position. Furthermore, it was essential that any change to the knuckle pad would not preclude full opening of the knuckle by means of the thrower.

While the invention has been described particularly with reference to the standard E coupler, it is not intended to be limited in application only to this coupler. The A. A. R. standard H Tightlock coupler and the AA. R. proposed type F Interlocking coupler would receive the same benefits and advantages from the invention as are afforded the E coupler. Furthermore, it is to be noted that the benefits are obtained in existing couplers merely by changing the knuckle to one embodying the invention.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

What I claim is:

1. In a car coupler, a head, a knuckle pivoted to said head about a vertical pivot pin, said knuckle having a hub portion with an opening for receiving said pin and having a rearwardly extending tail portion, and a knuckle thrower pivoted to said head at a point rearwardly of said pin, said knuckle having a pad thereon extending rearwardly from said hub portion and disposed intermediate said pin and the rearward end of said tail portion, said thrower having a forwardly extending arm having engagement with said pad to swing said knuckle about said pin from closed to open position upon rotation of said thrower, said pad when said knuckle is closed being located to one side of a line connecting the pivotal centers of said knuckle and said knuckle thrower and moving to the other side of said line as said knuckle opens, said pad having a surface thereon for operative contact by said thrower throughout the pivotal movement of said knuckle from closed to open position, said surface diverging throughout its knuckle thrower contact portion forwardly and laterally toward the nose portion of said knuckle from a plane which passes through the pivotal axis of said knuckle and which is tangent to the rearward portion of said surface.

2. A car coupler according to claim 1 wherein the knuckle thrower contact portion of said surface comprises a rearward portion which is convexly curved with respect to said plane and a forward portion which forms a continuation of said rearward portion and is reversely curved therefrom.

WILLIAM J. METZGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

